Oil burner



Jan. 1, 1935. ,L. F. SPEAR 01 BURNER Filed June 30, 1933 5 Sheets-Sheet 1 a LEw N F SPEAK {ITTORNEYS an 1935. L. F. 5pm 1,985,951

OIL BURNER Filed June 30, 1933 3 Sheets-Sheet law (sk V IN V EN TOR. 115mm]? SPEAK A TTORNEYS.

Patented Jan. 1, 1935 UNITED STATES PATENT OFFICE on. BURNER 'Leolyn Fcspear, Westfield, Mass., assignor to Gilbert a Barker Manufacturing Company, Springfield, Mass a corporation of Massachusetts Application June 30, 1933, Serial No. 678,428

' 20 Claims.

of a burner of this type which is better adapted for use'for general heating purposes, as for example in hot air furnaces, hot water heaters and steam boilers, than are the conventional burners of such general type used heretofore.

More particularly, it is an object of the invention to provide a burner of this type which is constructed to operate when so mounted that the common axis of the several combustion tubes is disposed horizontally, or substantially so, as distinguished from the usual mounting in which said axis is vertical.

According to this feature of the invention, the combustion tubes of the burner are inserted through an outer wall of the firebox and the burner ring and vaporizing provisions are so located as to be conveniently accessible from outside the firebox for cleaning and inspection. The burner ring, being accessible from outside the firebox, enables the lighting of the burner to be conveniently effected. With the conventional burner mounted according to prior practice, the entire burner is housed within the walls of the furnace and cleaning, inspection and repairs are difiicult. Also the capacity of the burner is limited by the size of the door openings available.

It is another object of the invention to provide improved means for vaporizing the fuel, preferably disposed in part outside thefirebox and in part inside the firebox, and arranged to operate at relatively low temperature and at a slower rate than usual to avoid as far as possible cracking of the oil and the relatively rapid formation of residue of a hard, fiinty, coke-like nature. Residue of this character is difficult to remove and it is preferable tovaporize the oil more slowly and avoid the formation of residue of this character. With the present plan of vaporization, such residue as is formed is more likely to be of a soft, tarry nature and easily removable.

The invention also has for an object the provision of a vaporizing chamber of relatively large area having labyrinth passages for the flow of oil therethrough, these provisions compensating for the low temperature available for vaporizing. The necessary amount of vapor is obtained at lower temperature by using a larger volume of oil in the vaporizer.

The invention has for another object to mount the vaporizer near the lower end of the burner ring and to feed the vapors to the lower portions of the fuel grooves therein,the vapors rising easily and spreading around the remainder of the grooves and the combustion chambers.

The invention also has for an object to provide improved means for controlling the air flow to the burner.

The invention has for a further object the provision of animproved arrangement of deflectors associated with the outlet ends of the combustion tubes.

The invention has for another object the provision of means enabling the burner to operate on the high-low fire principle, maintaining a low fire to keep the vaporizer warm during intervals in which there is no demandfor heat and a larger fire when there is a demand for heat.

Other objects will appear as the detailed description proceeds and will be pointed out in the appended claims. The invention will be disclosed with reference to the accompanying drawings, in which:-'

. Fig. 1 is a small scale-exterior and elevational view of a burner embodying the invention; Fig. 2 is a sectional view, drawn to a larger scale and taken on the line 2-2 of Fig. 1;

Fig. 3- is a cross sectional view taken on the line 3-3 of Fig. 2; I

Fig. 4 is a fragmentary sectional plan view taken on the line 4'4 of Fig. 1;

- Fig. 5 is an elevational view showing the inner end of the burner,certain parts being broken away to reveal interior construction;

Fig. 6 is a fragmentary sectional on the line 6-6 of Fig. 5;

Fig. '7 is a fragmentary sectional view taken on the line 7-7 of Fig. 3; and i Fig. 8 is a diagrammatical view showing conventionally a form of control for the burner.

view taken Referring to these drawings, the burner has an end frame which includes a hollow member 10 of the contour best shown in Fig. 3, and having a marginal embordering flange 11 (Fig. 5). This member in its. upper portion is semi-cylindrical in shape and in its lower portion'roughly rectangular in shape. It is set' into the wall w of a combination chamber C with the flange 11 abutting the outer face of said wall (Fig. 2). The member 10 is supported with its axis hori-' zontally disposed andwith its inner end projecting into the chamber C. The inner portion 10' of member 10 is cylindrical (Fig. 3) and such portion is connected to the wall 10 byvertical walls 11'. These walls 11' as well as a considerable portion of the bottom 'wall of member 10 project into the combustion chamber C and are exposed to the heat therein, as will be 'clear from Figs. 2 and 5.

The inner end face of member 10 is formed to provide a plurality of annular rings 12 (three as shown in Fig. 3) .which are supported in radially spaced concentric relation, and in similar relation with the cylindrical flange 10', by a series of angularly spaced and radially disposed connecting webs 13, leaving arcuate air spaces 14 between adjacent rings andoutside the outer ring and a central air space 15 within the inner ring.

Spider arms 16 support a central hub 17 from and walls of each groove 18 are formed with seats to receive a pair of perforated combustion tubes 19 which extend into combustion chamber C and aflord between them a primary combustion chamber 20. Between each combustion chamber- 20 is 'an intervening air chamber 21. Within the innermost tube 19 is a central cylindrical air chamber 22 and outside the outermost tube 19 is an outer annular air chamber 23 formed by'a tube'24 seated within the cylindrical portion 10' of member 10. p

A cover 25 rests against the inner ends of all the tubes 19 and tube 24 and has a flange 26 to' flt the periphery of tube 24. This cover is held in place by a stud 27, threaded into' hub 17 at one end and at the other end extending centrally through the cover and being threaded to receive a nut 28, which through the intermediary of a spring washer 29 clamps the cover to the tubes and the tubes to the frame member 10. This cover, as shown in Fig. 5, closes the inner end of the air chambers 21 and has a circular series of openings 30 for each combustion chamber 20, forming outlets therefor. Thecover also closes oil'- the centralair chamber .22 at its inner end except for a circular series of holes 31, arranged closely adJacent to the innermost tube 19. A circular series of holes 32 in cover 25 afford outlets for the outer air chamber 23.

A secondary combustion chamber 33 is provided within a partly conical shield 34 which has,

a cylindrical flange 35 tightly fltting over the flange 26 and held in place thereby. Within the chamber 33 is a circular deflector plate 36 mounted on stud 27 and held in place thereon by and between a pair of nuts 3'7. The deflector is spaced from cover 25 and is of sufficient diameter so as to lie in the path of the air streamsissuing through holes 31 andthe gases issuing through openings 30 from the innermost combus tion chamber 20. The member 34 serves. to deflect inwardly the air streams issuing from the holes 32 from the outer air chamber and the gases issuing through openings 30 from the outermost combustion chamber 20. The gases from the several combustion chambers are caused to mix with each other and with additional air supplied in inner and outer streams which encompass the gases with the end in view of completely consuming the fuel in the high temperature zone within chamber 34.

The lower portion of member 10 is formed with a vaporizing chamber. To secure a chamber of adequate area, said portion of member, 10 is extended outwardly beyond flange 11 (Fig. 2)

to provide a horizontally disposed box 38 pro,-

viding within it a chamber 39. Between the inner wall 40 of this-box and the burner rings ing chamber, part of which as will'be c ear from Fig. 2, lies in the combustion chamber C. Communication between the channel 41 and grooves 12 is afforded by two upwardly and inwardly converging box-like extensions 42, affording within them channels 43. The several rings 12 are slotted at the points where they pass through channel 43 as indicated at 44 in Figs. 3 and 7, so that vapor can enter each groove 12 at two Iangularly'spaced locations, both of which are preferably near the lower part of the burner. Liquid-fuel is fed into the vaporizing chamber 39 at one other corner thereo by way of a pipe 45, by any suitable means w ch will maintain the oil within the desired limits of level therein. The floor of this chamber preferably slopes downward from its inner end deflned by walls 11' to itsouter end where pipe 45 enters. This chamber is divided into a plurality of longitudinal channels 46 by a plurality of upstanding partitions 47. Oil flows from pipe 45 into one end of the outermost channel ,46 and flows along the same to the opposite end thereof where an opening 48 is provided which allows the oil to pass into the middle channel and flow therealong in the opposite direction until it reaches'that end of the .middle channel which lies nearest pipe 45. Here another opening 43 is provided to enable the oil to flow into-the inner channel 46 and along the same. The inner channel 46 communicates with channel 41 by way of 'an movable covers 52 which when removed, allow easy access to all parts of the chamber for cleaning. In this instance, the upper closure for the chamber also includes a fixed central section 53 used as a support fora fan later to be described,

but in cases where such fan is not used, this central part 53 may be dispensed with. However, this part 53, because it is narrow, does not interfere materially with the cleaning operation. The covers 52 are supported on ledges 54 formed on and projecting inwardly from box 38. A gasket 55 is preferably interposed between each cover 52 and its supporting ledges 54 and the cover is clamped in place by a wing nut 56 threaded on the upper end of a stud 5'7 flxed in and upstanding fromthe lower wall of box 38. It is to be noted that the cover is spaced from the upper ends of partitions 47 so that vapor can flow over the upper edges of such partitions. The channel 41 is closed at its upper end by a wall 58.

For initially heating the lower parts of the burner to start the vaporizing action, a wick 59 is mounted within each extension 42., This wick extends vertically upward in the slot formed in the several rings 12 and is held in place between the adjacent cut ends of such rings. The wick has doubled over portions 60 projecting horizontally inwardly therefrom at intervals, one such portion for and extending into each fuel groove-18. The lower end of the wick extends close to thelower wall of channel 14 and far enough to be immersed in the oil which at starting covers the floor of this channel. An open-- ing 61, normally closed by a pivoted cover 62, is provided in the outer wall of each extension 42 to enable a lighter to be passed into the chamber 43 to ignite the wick.

It is sometimes desirable to provide a forced draft for the burner and, in such cases, a suitable fan 63. is provided. As herein shown, the fan is driven, by an electric motor 64 supported through the intermediary of a suitable bracket 65 from the central part 53 of the upper wall of the vaporizing chamber. It will be noted that the covers 52 may be removed without removing the motor support 65. The fan 63, if

used, is preferably enclosed within a housing 66 pivoted at 56 to the upper part of flange 11. This housing has a central opening 6Bv as an intake for air and an opening 69 extending radially from the central opening to the lower edge of the housing to clear the bracket so that the housing may be swung upwardly to gain access to the burner without first removing the bracket 65'. The lower edge of housing 66 rests upon the covers 52 which close the lower end of the fan chamber 70.

Means are provided for controlling the air supply to each of the several air chambers of the burner and preferably such means are arranged, as shown, to enable the supply to each chamber to be varied independently of the supply to any other chamber. As shown, the air supply to the central chamber 22 is controlled by a circular plate 71 which is mounted to move axially inwardly or outwardly in the central opening 15 in the burner base.-- The inner wall of the innermost fuel groove converges inwardly.- Therefore, as plate 71 is moved in or out, the annular space 73 (see Fig. 3)' between its peripheral edge and the inner peripheralwall of ring 12 will be decreased or increased, respectively, in area. Any desired mounting of the plate 71 suitable to accomplish the stated purpose may be used. A simple but very desirable form of mounting is that shown which consists .plane or some may be turned more thanothers to tilt the plate somewhat and thus allow for a larger flow of air into one part of chamber 22 than at another.

The air supply to the two annular air chambers and to the outer annular air chamber 23 I is controlled in a generally similar way by arcuate damper plates '74 (Fig. 3) each adjustably secured by a plurality of screws 75 threaded into the webs 13. Each of these plates extends along its air opening 14 from one box 42 to the other as clearly shown in Fig. 3. These plates may be moved, the one independently of the other, in

' the same ways as described in connection with plate '15. r The burner is adapted to operate on the highlow fire principle and, when so operated,'I-provide a pair of partitions 76 in each combustion chamber 22. The low fire which is maintained in the intervals when there is no demand forheat from the burner, is preferably confined to the lower section of the burner for the purpose of keeping the vaporizing chamber warm. To

' shield the low fire section of each combustion i1 burners. I The operation of the burner will. next be described. In the first instance it willbe neceslchamber'from the effects of air passing into the then idle upper part thereof, the partitions 76 are used. As shown, the twopartitions of each pair are diametrically opposed and divide to a certain extent the upper half from the lower half of the combustion chamber in which-they are located. But these partitions are adjustable and may be moved toincreasethe area of the low I fire-'section' and, diminish the area of the remaining section or to decrease the area of the low fire section and increase the area of the remaining section. It, will be seen from Fig; 5 that one partition of each pair is secured to one of the two tubes 19 between which it is located,

and the other is secured to the other of said tubes. Consequently, by turning these two tubes, the partitions may be moved to any desired ane '1 gular position. They might, for example,-be moved more closely toward the vapor conduits 43 and thus diminish the area of -the.low fl re section of combustion chamber 22. It is obvious that the partitions, for any one combustion chamber 22 may be adjusted independently of those for any other of the chambers 22.

The partitions do not wholly close of! the space between adjacent tubes19.v The ,unse

cured edge of each partition-does notabutthe adjacent tube 19. Also such edge is preferably. tapering and diverges inwardly from the ad- J'acent tube so that there is a progressive- 1y increasing degree of communication between the .two sections of each combustion, chamber, increasing in a direction towardthe outlet of the chamber. The partitions '76 prefmain elements necessary to the operation of .the

burner.' The supply of oil to the vaporizer for high fire is controlled by a valve 80, normally closed by a spring 81 and capable of being opened, by a solenoid 82 when the latter is energized, as by the closing of the electric circuit 83- by the.

thermostat 84. Included in this circuit is themfan motor 64. There is a by-pass 85 around valve and this by-pass is suitably controlled as by a hand operated valve 86, so as to afford a constant flow of oil to the. vaporizer but at a relatively low rate sumcient for'maintaining. in the vaporizer enough oil to produce enough vapor to support a satisfactory low fire in the. burner. When there is a demand for.heat;,.the

thermostat 84 closes circuit83, {therebyenergizing the solenoid 82 which .opensvalve 80 and admits oil to the vaporizerate faster rate and provides therein the .larger supply of oil necessary to produce the requisitetamount of vapor to maintain the high flre in the burner.

The control means has beenshown merelyin conventional form but sufliciently to illustrate the principle involved. Any of the standard controls now available in the marketfor doing the work above outlined may be as desired, as may also anyof the safety devicesf which are commonly used in connection. with sary to admit oil into the vapolrizing' chamber done by opening wide the valv186. '"I'herith valve may be closeddown to the low jire pos tion again. .Thewicks are then ig ited until the wicks 59 are saturated. This may be.

serting a lighter through the openings 61. After a short interval, the heat from the burning .oil will'have warmed the walls of the vaporizing chambersufllciently to start vaporization of the oil therein and the normal low fire" operation then ensues. With the restricted rate of supply of oil then available (through the by-pass pipe 85 only),the outermost part only of-the lie between the ducts 42, these are not ordinarily necessary and I prefer .to omit them because, by so doing, I am enabled to secure a rather lean mixture on low fire, in which case combustion tends to be localized at or near the two wicks 59. The object of the low fire is simply to maintain the vaporizer warm enough so that there will be a relatively quick response when the main supply of fuel is turned on.

When more heat from the burner is needed, the valve 80 is opened, usually although not necessarily in an automatic manner, as by the thermostat 84. Oil then enters the vaporizing chamber at a higher rate and soon covers a much larger portion of the sloping floor of the chamber. But because of this sloping floor, there is available increase in effective vaporizing surface more or less in proportion .to the increase inthe supply of fuel and a much larger,v

volume of oil is vaporized. There will bev initially a rapid rise in the level of oil in the vaporizing chamber, when valve 80 is opened, followed by a gradual recession to a lower level due to.

the increased temperature of the walls of the vaporizing chamber afterthe burner has been in operation for some time. A large volume of vapor will be produced,more than can be consumed at the ducts 42,and the vapors will rise and'spread about the several combustion chambers. It is thought preferable on high fire to supplement the natural draft by the forced' draft due to fan 63 because of the tendency of the' latter to afford a more uniform supply of air to the several combustion chambers than would be available with natural draft alone. The adjustable air control members '74 are important in a burner of this type because they enable compensation for inequalities in draft conditions which might otherwise exist. For example, if the air supply is too great near the lower and insufficient near the upper quadrant of the burner, the rings '74 may be moved in at the bottom and out at the top into a somewhat tilted position to overcome the condition.

After the burner has delivered the needed amountof heat, valve 80 is closed, either automatlcally or otherwise and fan 63 isstopped. There ensues, after the closing of valve 80 and the consequent reduction of the oil supply, a

gradual recession in the level of oil in the vaporizing chamber and a gradual diminishing of the volume of vapor produced until the burner is again operating at the low fire condition with combustion localized largely at or near the ducts 42.

The extent to which the vaporizing chamber extends into the combustion chamber controlsthe. rate of vaporization of the oil and the best ,which is so diflicult to remove.

tant advantage of convenient access to all parts which may require adjustment or cleaning. All such parts may be reached from outside the fire box. By swinging open the casing 68, access is had to'the holes 61 for initially lighting the burner or for inspection of the low fire operation of the burner. Access is also had to the various air control devices 74. The vaporizing chamber can be reached for inspection or cleaning by removing the covers 53. With this burner, the grooves 18 should not need cleaning because vapor only is supplied to them except when the burner is initially lighted. Any residue shouldbe foundin the outer portion 39 of the vaporizing chamber, all portions of which are accessible for easy cleaning by removing the covers 52. The casing 68 does not need to be lifted to.

to be inserted through a side wall of the com-' bustion chamber. It is not necessary, as heretofore, to mount the burner entirely within the combustion chamber, where it is dimcult to assemble and adjust the parts.' So also, byreason of the improved mounting, the burner need no longer be limited in size or capacity by the size of the door openings into the combustion chamber.

. The construction and arrangement of the vaporizing chamber is thought to be important as enabling satisfactory operation of a burner of the combustion tube type with the axes of the combustion tubes disposed horizontally rather than vertically as heretofore. It will, of course,

be obvious that such axis need not be exactly horizontal as shown, and that it may be tilted up or down within substantial limits and stillfunction properly. The vaporizing chamber, lo-

cated near the lower quadrant of the burner, feeds vapor into that quadrant for the low fire. When more vapor is produced, the vapors rise and spread to the other quadrants to secure high fire. The disposition of the vaporizing chamber in part inside and in part outside the combustion chamber enables vaporization at lower temperatures with less liability of cracking the oil and throwing down the hard, coke-like residue The large area of the chamber with its labyrinth passages provides suflicient vaporizing surface so that the requisite volume of vapor can be produced at the lower temperature. By having the vaporizing chamber partly outside and partly inside the combustion chamber one can control the vaporizing temperature by moving the vaporizing chamber in or out of the combustion chamber, accordingly as more or less heat is required for the purpose, whereas if the vaporizing chamber were located wholly inside the combustion chamber, such easy control over the vaporizing temperature is not possible. The sloping fioor of the vaporizing chamber enables the eflective the small rate of feed of oil to the vaporizer on low fire operation, only a small part and the most remote and coolest part of the walls of the chamber are effective to vaporize the oil, while with an increase in the rate of feed of the oil more and more of the floor is covered and there is a progressive increase in the effective area of vaporizing surface and also a progressive increase in the temperature of such surface as the oil approaches the burner .ring.

What I claim is:.

1. A vapor burner, sleeves mounted one within the other and affording inthe space between them a combustion chamber, at least one of said sleeves having openings therethrough for the admission of air to said chamber, a closure for one end of said chamber, said closure mounted in a non-horizontal plane such that it is incapable of retaining liquid fuel thereon,- and means to supply fuel vapor into said chamber near the closed end thereof. a

2. The combination with a fire box, of a combustion tube burner, having its combustion tubes disposed with their common axis at a substantial angle to the vertical and adapted to be inserted through a side wall of the firebox,a member connected with said tubes and affording walls enclosing a vaporizing chamber, such walls dis- .posed in part outside and in part inside said firebox and derivin'gheat therefrom to vaporize fuel, meansto supply liquid fuel to said chamber near one end thereof, and a conduit connecting said chamber near its other end to the space passage within the innermost ring, a pairof perforated combustion tubes projecting substantially horizontally inward from one face of each ring and forming with the'latter a combustion chamber, a vaporizing chamber connected to said member near its lower end and extending substantially horizontally outward therefrom,

and means for supplying oil to said chamber, said member being provided with a vapor duct extending from said chamber across the other face of each of said rings, and said rings having openings affording communication between each combustion chamber and said duct.

4. An oil burner, comprising, a hollow ringlike member adapted to be set into the side wall of a firebox, said member having within it a plurality .of spaced concentric rings with annular air passages between them and a central air passage within theinnermost ring, a pair of perforated combustion tubes projecting substantially horizontally inward from one face of each ring and forming with the latter a'combustion chamber, a vaporizing chamber connected to said member "near its lower end and extending substantially horizontally outward therefrom, means for supplying oil to said chamber, said member being 'provided with a vapor duct extending from said chamberacross the other face of each of said rings, and said rings having openings affording communication between each combustion chamber andsaid duct, and a wick mounted in said duct and projecting into at least comprising, a pair of' one of said combustion chambers. and-extending mm said chamber.

5. 'An oil burner, comprising, a 'hollow ring-li lre -member adapted tobe set into the side wall of a firebox, said member having within it a plurality of spaced concentric rings with annular air passages between them and a central air passage within'the innermost ring, a pairof perforated combustion tubes projecting substantially horinear its lower end and'extending substantially horizontally outward therefrom, means for supplying oil to said chamber, said member being provided with a vapor duct extending from said chamber across the other face of each of said rings, said rings havingopeningsaflording communication between each combustion chamber and said duct, and means for varying the effective area of said several air passages the one independently of the other.

6. An oil burner, comprising, a hollow ringlike member adapted to be set into the side wall.

said member near its lower end and extending substantially horizontally outward therefrom,

means for supplying oil to said chamber, said member being provided with a pair of vapor ducts extending upwardly from said chamber in laterally spaced relation and each extending "across the other face of each ring, said rings having openings therethrough affording communication between each combustion chamber and each duct, said ducts crossing said annular air passages and dividing each of them into a relatively large section and a relatively small section, the smaller sections being located between the ducts, and means vfor independently varying the effective area of said larger annular air passages.

7. An oil burner, comprising, ahollow ring-- i like member adapted to be set into the side wall of a firebox, said member having within it a plurality of spaced concentric rings with annular air passagesbetween them and a central air passage within the innermost ring, a

pair of perforated combustion tubes projecting substantially horizontally inward from one face of each'ring and forming with the latter a combustion chamber, a vaporizing chamber connected to said member near its lower end andextending substantially horizontally outward therefrom, means for supplying oil to said chamber, said member being, provided with a pair of vapor ducts extending upwardly from said member in laterally spaced relation and each extending across the other face of each ring,

of! at least in part the lower portion of each combustion chamber which portion is in communication with said ducts from the remainder thereof.

8. An oil burner, comprising, a hollow ringlike member adapted to be set into the side wall-of a firebox, said member having within it a plurality of spaced concentric rings with annular air passages between them and a central air passage within the innermost ring, a pair of perforated combustion tubes projecting substantially horizontally inward from one face of each ring and forming with the latter a combustion chamber, a vaporizing chamber connected to said member near its lower end and extending substantially horizontally outward therefrom, means for supplying oil to said chamber, said member being provided with a vapor duct extending from said chamber across the other face of each of said rings, and openings through said rings afiording communication between each combustion chamber and said duct, and forced draft means for supplying air through said passages.

9. An ofl burner, comprising, a hollow ring- Y like member adapted to be set into the side wall 'of a firebox, said member having within it a plurality of spaced concentric rings with annular air passages between them and a central air passage within the innermost ring, a pair of perforated combustion tubes projecting substantially horizontally inward from one face of each ring and forming withthe latter a combustion chamber, a vaporizing chamber, connected to said member near its lower end and extending substantially horizontally outward therefrom,

means for supplying oil to said chamber, saidmember being provided with a vapor duct extending from said. chamber across the other face of each of said rings, said rings having openings therethrough affording communication between each combustion chamber and said duct, a cover closing the outer face of said hollow ring-like member except for an air inlet opening, and a fan within the space enclosed by said cover and member.

10. An oil burner, comprising, a hollow ringlike member adapted to be set into the side wall of a firebox, said member having within it aplurality of spaced concentric rings with an-.

nular air passages between them and a central air passage within the innermost ring, a pair of perforated combustion tubes projecting substantially horizontally inward from one face of each ring and forming with the latter a combustion chamber, a vaporizing chamber connected to said member near its lower end and extending pose said fan and rings without removing the fan.

11. An oil burner, comprising, a hollow ringlike member adapted to be set into the side wall of a firebox, said member having within it a plurality of spaced concentric rings with annular air passages between them and a central air passage within the innermost ring, a pair of perforated combustion tubes projecting substantially horizontally inward from one face of each ring and forming with the latter a combustion chamber, a vaporizing chamber connected to said member near its lower end and extending substanti'alhr horizontally outward therefrom, means for supplying oil to said chamber, said member being provided with a vapor duct extending from said chamber across the other face of each of said rings, said rings having openings therethrough affording communication between each combustion chamber and said duct,

a power driven fan mounted centrally on the top wall of said vaporizing chamber, a cover connected to said member and closing the outer face thereof except for an air inlet opening and enclosing said fan, said opening being constructed to permit the cover to be moved to expose said fan and rings without removing the fan, and removable covers for said vaporizing chamber disposed one on each side of said fan.

7 12. In an oil burner, a pair of ringniembers mounted one within the other and afiording an air space between them, a pair of perforated combustion tubes extending, from each member and affording between them a combustion chamber, and an air control member for said space comprising an arcuate member mounted to move into and out of said space in an axial direction and having peripheral surfaces cooperating with the adjacent peripheral surfaces of said rings, one set of surfaces converging in the direction of said tubes.

13. "In an oil burner, a pair of ring members mounted one within the other and affording an air space between them, a pair of perforated combustion tubes extending from each member and afiording between them a combustion chamber, and an air control member for said space comprising an arcuate member mounted to move relatively to said members to vary the air supply to said space and capable of being moved to different degrees at different points in its a'rcuate extent.

14. In an oil burner, a plurality of pairs of perforated combustion tubes mounted in spaced concentric relation and with their common axis at a substantial angle to the vertical, each said pair affording between them a combustion chamber, the space between one tube of each pair and the next adjacent tube of the next pair constituting an intermediate air chamber, a tube encompassing the outermostcombustion tube in spaced relation, the space between said last named pair of tubes constituting an outer air chamber, a member connected to all said tubes at one end and closing said'combustion chambers, means for supplying fuel to each bustion chambers, openings in said closure member allowing egress of air from the outer air chamber, and deflecting means for forcing the air emitted from the outer air chamber inwardly to mix with the gases issuing from the combustion chambers.

15. lnzan oil burner, a plurality of pairs of perforated combustion tubes mounted in spaced concentric relation and with their common axis at a substantial angle to the vertical, each said pair aflording between them a combustion from the outer air chamber, the space between one tube of each pair and the next adjacent tube of the next pair constituting an intermediate air chamber, and the space within the innermost tube constituting an inner air chamber, a tube encompassing the outermost combustion tube in spaced relation, the space between said last named pair of tubes constituting an outer air chamber, a member connected to all said tubes at one. end and clos-' ing said combustion chambers, means for supplying fuel to each combustion chamber, a member on the other ends of said tubes forming a closure for all the intermediate air chambers but not for the combustion chambers, openings in said closure member allowing egress of air chamber and from the inner air chamber near the innermost tube, and dethe space within the innermost tube constituting an inner air chamber, a tube encompassing the outermost combustion tube in spaced relation,

the space between said last named pair of tubes from said conduit,

constituting an outer air chamber, a member connected to all said tubes at one end and'closing said combustion chambers, means for supplying fuel to each combustion chamber, a member on the other ends of said tubes forming a closure for all the intermediate air chambers but not for the combustion chambers, openings in said closure member allowing egress of air from the outer air chamber and from the inner air chamber near the innermost tube, power means for'forcing air into said several air chambers, and deflecting means'for forcing the air emitted from the outer air chamber inwardly and the air emitted from the inner air chamber outwardly to mix with the gases issuing from -the combustion chambers therebetween.

17. An oil burner comprising, a substantially horizontally disposed box-like member affording within it a vaporizing chamber and upstanding from one edge thereof a member formed with a plurality of rings mounted in air spaced relation, the box-like member being approximately t'angentially disposed relative to the outermost ring, a pair of perforated combustion tubes for each said ring projecting therefrom in a direction opposite to that in'whichsaid box-like member projects,- a vapor conduit leading from the vaporizing chamber into the lower portion of each combustion chamber, an oil supply for said chamber entering and means in said chamber to conduct the oil from said inlet in a labyrinthian path in its course toward said conduit.

18. A vapor burner, comprising, a pair of sleeves mounted one within the other and affording in the space between them a combustion chamber, at leastone of said sleeves having openings therethrough for the admission of air to said chamber, a closure for one end of said chamber, said closure mounted in a non-hori- 1,9ss,es'r

1 ing liquid fuel thereon, a member connected to chamber,

ber.

the same at a' point remote sively higher levels. zontal plane such that it is incapable of retain- I Y said closure and deriving heat therefrom to vaporize liquid fuel and having within it a vaporizing chamber, said member having a wall forming a floor for said chamber which floor slopes from a highlevel adjacent said closure to a lower level at a location remote from said closure, vapor outlet means connecting said chamber near the high level part thereof to one peripheral portion only of said combustion chamber near the closed end thereof, said member having an inlet for liquid fuel near the low level end thereof and except for said inlet and said out.- let means being closed,and means for selective-- ly supplying-fuel at different rates to said inlet for covering different areas of said floor and thereby varying the amount of vapor produced in said chamber. In

, 19. A vapor burner, comprising, a pair of sleeves mounted one within the other and affording in the space between them-a combustion chamber, at least one of said sleeves having openings therethrough for the admission of'air to said chamber, a closure for one end of said said' closure'mounted in a non-horizontal plane such that it is incapable of retaining liquid fuel thereon, a member connected to said closure and deriving heat therefrom to vaporize liquid fuel and having within it a vaporizing chamber, said member having a wall forming a floor for said chamber which floor slopes from a high level adjacent said closure to a lower level at a location remote 'from said closure,

vapor outlet means connecting said chamber.

near the high level part thereof to one peripheral portion only of said combustion'chamber near the closed end thereof, said member having aninlet for liquid fuel near the-low level end thereof and except for said inlet and said outlet means being closed, and selectively operable means for supplying liquid fuel to said inlet at a relatively low and a relatively high rate sufficient to cover a small and a larger area, respectively, of said floor, whereby when the small area only of said floor is covered only sufllcient vapor is produced to maintain combustion localized in said section of the combustion chamber and when the larger area of said floor is covered the vapor supply is increased and combustion spreads to all sections of said combustion cham- 20. In'combination, a combustion tube burner including a pair of combustion tubes providing in the space between them a combustion chamber and a closure for one endof said chamber,

-a hollow member connected to said closure and and providing within it' deriving heat therefrom avaporizing chambe said member having a wall which forms a floor for the vaporizing chamber and such floor sloping from ahigh level at the side adjacent said closure to a low level.

at the remote side, said member'having vapor outlet means connecting the high side of saidchamber to said combustion chamber, said member having a liquid fuel inlet near the low level .side of said chamber, and a series of substantially parallel ribs upstanding from the floor and substantially paralle 'ng said sides andforming between them a series of channels interconnect-.

ed at their ends to compel fuelflto traverse the floor at the lowest level part and then successivelyrtraverse parts of said floor at progres- LEQLYN' F. SPEAR. 

